The subject invention relates to standard measuring weights which are typically used in conjunction with a balance for very accurately weighing quantities of matter. These weights are applicable in scientific or laboratory work, as well as in measuring the weight of retail goods sold to the public. As such, it can be appreciated that they are very delicate, precision instruments which must approximate their true value within a very fine tolerance.
Generally, known measuring weights include a body portion having a threaded bore, and a cap portion which is screwed into the bore of the body portion. Typically, adjustment particles are included in the bore of the weight and sealed therein by the cap. These particles, which may be as fine as dust particles, are added to the weight at the time of manufacture, and serve to bring the weight to within a very fine tolerance of its true value. After a period of use it may be necessary to add additional adjustment particles to the weight to keep it accurate. An example of such an instance is after polishing of the weight. More particularly, it is often desirable that a weight, after it has been used for a period of time, be polished. However, attendant with polishing is the loss of material and weight. Accordingly, in order to bring the weight to within an acceptable tolerance of its true weight additional adjustment particles must be added.
Several shortcomings have been associated with the known standard measuring weights described above. One shortcoming relates to improper use of the weight.
Ideally, the cap of the weight should never be removed except at appropriate times when adjustment of the weight is necessary, and then only by a technically qualified person. However, it has been often experienced that users, for one reason or another, remove the cap portion from the body of the weight, often causing part or all of the adjustment particles contained in the bore thereof to empty out. It should be appreciated that these adjustment particles may be very fine dust-like particles, which may be easily lost and practically impossible to replace by the user. Of course, if some of the adjustment particles are missing, the weight, which must necessarily be a precision instrument, is no longer accurate.
Another shortcoming of known measuring weights is directly related to the above described misuse. More particularly, although loss of all or part of the adjustment particles renders the weight inaccurate, the relatively small difference in weight would not be apparent to an indiscriminate subsequent user. As a result, an inaccurate weight, instead of a precision instrument will be in continuous use. The effect of such use especially in laboratory work and other applications requiring a high degree of precision can be readily appreciated.
A further shortcoming of known measuring weights relates to their cap or cover portions. More particularly, the cap or cover portions of known measuring weights are generally so configured as to enable a user to grip the weight with only one hand. It may be readily appreciated that as such, movement of weights weighing on the order of fifty to one hundred pounds can be quite cumbersome.
Accordingly, it is an object of the subject invention to provide a new and improved standard measuring weight in which inaccuracies caused by improper use is virtually eliminated.
It is another object of the subject invention to provide a new and improved measuring weight in which even if the weight has been tampered with, a subsequent user can readily ascertain that the weight is not at its proper value.
It is a further object of the subject invention to provide a new and improved measuring weight in which weights on the order of fifty to one hundred pounds may be more easily handled and moved.